/*
 * Copyright (C) 2010 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.testing.Helpers;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.NavigableSet;
import java.util.TreeSet;

import org.junit.Ignore;

/**
 * A generic JUnit test which tests operations on a NavigableSet. Can't be invoked directly; please
 * see {@code NavigableSetTestSuiteBuilder}.
 *
 * @author Jesse Wilson
 * @author Louis Wasserman
 */
@GwtIncompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class NavigableSetNavigationTester<E> extends AbstractSetTester<E>
{

    private NavigableSet<E> navigableSet;
    private List<E> values;
    private E a;
    private E b;
    private E c;

    @Override
    public void setUp() throws Exception
    {
        super.setUp();
        navigableSet = (NavigableSet<E>) getSet();
        values =
                Helpers.copyToList(
                        getSubjectGenerator()
                                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
        Collections.sort(values, navigableSet.comparator());

        // some tests assume SEVERAL == 3
        if (values.size() >= 1)
        {
            a = values.get(0);
            if (values.size() >= 3)
            {
                b = values.get(1);
                c = values.get(2);
            }
        }
    }

    /**
     * Resets the contents of navigableSet to have elements a, c, for the navigation tests.
     */
    protected void resetWithHole()
    {
        super.resetContainer(getSubjectGenerator().create(a, c));
        navigableSet = (NavigableSet<E>) getSet();
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(ZERO)
    public void testEmptySetPollFirst()
    {
        assertNull(navigableSet.pollFirst());
    }

    @CollectionSize.Require(ZERO)
    public void testEmptySetNearby()
    {
        assertNull(navigableSet.lower(e0()));
        assertNull(navigableSet.floor(e0()));
        assertNull(navigableSet.ceiling(e0()));
        assertNull(navigableSet.higher(e0()));
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(ZERO)
    public void testEmptySetPollLast()
    {
        assertNull(navigableSet.pollLast());
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(ONE)
    public void testSingletonSetPollFirst()
    {
        assertEquals(a, navigableSet.pollFirst());
        assertTrue(navigableSet.isEmpty());
    }

    @CollectionSize.Require(ONE)
    public void testSingletonSetNearby()
    {
        assertNull(navigableSet.lower(e0()));
        assertEquals(a, navigableSet.floor(e0()));
        assertEquals(a, navigableSet.ceiling(e0()));
        assertNull(navigableSet.higher(e0()));
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(ONE)
    public void testSingletonSetPollLast()
    {
        assertEquals(a, navigableSet.pollLast());
        assertTrue(navigableSet.isEmpty());
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(SEVERAL)
    public void testPollFirst()
    {
        assertEquals(a, navigableSet.pollFirst());
        assertEquals(values.subList(1, values.size()), Helpers.copyToList(navigableSet));
    }

    @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
    public void testPollFirstUnsupported()
    {
        try
        {
            navigableSet.pollFirst();
            fail();
        }
        catch (UnsupportedOperationException e)
        {
        }
    }

    @CollectionSize.Require(SEVERAL)
    public void testLowerHole()
    {
        resetWithHole();
        assertEquals(null, navigableSet.lower(a));
        assertEquals(a, navigableSet.lower(b));
        assertEquals(a, navigableSet.lower(c));
    }

    @CollectionSize.Require(SEVERAL)
    public void testFloorHole()
    {
        resetWithHole();
        assertEquals(a, navigableSet.floor(a));
        assertEquals(a, navigableSet.floor(b));
        assertEquals(c, navigableSet.floor(c));
    }

    @CollectionSize.Require(SEVERAL)
    public void testCeilingHole()
    {
        resetWithHole();
        assertEquals(a, navigableSet.ceiling(a));
        assertEquals(c, navigableSet.ceiling(b));
        assertEquals(c, navigableSet.ceiling(c));
    }

    @CollectionSize.Require(SEVERAL)
    public void testHigherHole()
    {
        resetWithHole();
        assertEquals(c, navigableSet.higher(a));
        assertEquals(c, navigableSet.higher(b));
        assertEquals(null, navigableSet.higher(c));
    }

    /*
     * TODO(cpovirk): make "too small" and "too large" elements available for better navigation
     * testing. At that point, we may be able to eliminate the "hole" tests, which would mean that
     * ContiguousSet's tests would no longer need to suppress them.
     */
    @CollectionSize.Require(SEVERAL)
    public void testLower()
    {
        assertEquals(null, navigableSet.lower(a));
        assertEquals(a, navigableSet.lower(b));
        assertEquals(b, navigableSet.lower(c));
    }

    @CollectionSize.Require(SEVERAL)
    public void testFloor()
    {
        assertEquals(a, navigableSet.floor(a));
        assertEquals(b, navigableSet.floor(b));
        assertEquals(c, navigableSet.floor(c));
    }

    @CollectionSize.Require(SEVERAL)
    public void testCeiling()
    {
        assertEquals(a, navigableSet.ceiling(a));
        assertEquals(b, navigableSet.ceiling(b));
        assertEquals(c, navigableSet.ceiling(c));
    }

    @CollectionSize.Require(SEVERAL)
    public void testHigher()
    {
        assertEquals(b, navigableSet.higher(a));
        assertEquals(c, navigableSet.higher(b));
        assertEquals(null, navigableSet.higher(c));
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(SEVERAL)
    public void testPollLast()
    {
        assertEquals(c, navigableSet.pollLast());
        assertEquals(values.subList(0, values.size() - 1), Helpers.copyToList(navigableSet));
    }

    @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
    public void testPollLastUnsupported()
    {
        try
        {
            navigableSet.pollLast();
            fail();
        }
        catch (UnsupportedOperationException e)
        {
        }
    }

    @CollectionSize.Require(SEVERAL)
    public void testDescendingNavigation()
    {
        List<E> descending = new ArrayList<>();
        for (Iterator<E> i = navigableSet.descendingIterator(); i.hasNext(); )
        {
            descending.add(i.next());
        }
        Collections.reverse(descending);
        assertEquals(values, descending);
    }

    public void testEmptySubSet()
    {
        NavigableSet<E> empty = navigableSet.subSet(e0(), false, e0(), false);
        assertEquals(new TreeSet<E>(), empty);
    }

    /*
     * TODO(cpovirk): more testing of subSet/headSet/tailSet/descendingSet? and/or generate derived
     * suites?
     */

    /**
     * Returns the {@link Method} instances for the test methods in this class that create a set with
     * a "hole" in it so that set tests of {@code ContiguousSet} can suppress them with {@code
     * FeatureSpecificTestSuiteBuilder.suppressing()}.
     */
    /*
     * TODO(cpovirk): or we could make HOLES_FORBIDDEN a feature. Or we could declare that
     * implementations are permitted to throw IAE if a hole is requested, and we could update
     * test*Hole to permit IAE. (But might this ignore genuine bugs?) But see the TODO above
     * testLower, which could make this all unnecessary
     */
    public static Method[] getHoleMethods()
    {
        return new Method[]{
                Helpers.getMethod(NavigableSetNavigationTester.class, "testLowerHole"),
                Helpers.getMethod(NavigableSetNavigationTester.class, "testFloorHole"),
                Helpers.getMethod(NavigableSetNavigationTester.class, "testCeilingHole"),
                Helpers.getMethod(NavigableSetNavigationTester.class, "testHigherHole"),
        };
    }
}
